Charles Ellicott Commentary Deuteronomy 6:15

"for Jehovah thy God in the midst of thee is a jealous God; lest the anger of Jehovah thy God be kindled against thee, and he destroy thee from off the face of the earth." — Deuteronomy 6:15 (ASV)

From off the face of the earth. —Literally, of the ground. Absolute extermination is threatened by the fire of His jealousy.